Trafag Italia Srl
Via Cremona 1
20025 Legnano (Mi)
Tel. +39 0331 59 23 97
Fax +39 0331 59 98 15
www.trafagitalia.com
info@trafagitalia.com
INSTRUCTIONS MANUAL
BIMETAL THERMOMETERS
Instruction H21017a
05/2017
BIMETAL THERMOMETERS
TYPE: TMT501, TMT502
1 GENERAL WARNINGS
1.1 Instruments measuring range
Verify that measuring range of the instrument is suitable with wor-
king conditions of the circuit/plant. Maximum process temperatu-
re must remain within the instrument measuring range, identified
on dial with two black triangles.
1.2 Admitted over temperatures
Accidental over temperatures are admitted for short periods, provi-
ded that they remain within the values indicated in the datasheet.
1.3 Ambient temperature
Instruments are designed to work with an ambient temperature
between -20°C/+60°C (-4°F/+140°F). Different ambient tempera-
tures could give wrong indications or to damage the instrument. IT
is recommended to verify that the instrument installation position
is not subject to direct heat sources, both for convention or radia-
tion: if this is not possible, please foresee a protective screen.
1.4 Mechanical vibrations
Verify that chosen position for the installation is not subjected to
continuous mechanical vibrations, because this will cause accuracy
errors and shorter working life of instrument. If this is not possi-
ble, it is recommended to use instruments filled with dampening
liquid.
2 INSTALLATION
2.1 Process installation
The thermometers must be installed in a thermowell that is sui-
table to the line or to the tank where the temperature is to be me-
asured. It is also necessary to verify that the thermowell is suitable
for the installation of the thermometer. With reference to the figu-
re N° 3 is necessary to verify that:
■
The minimum length “S” (see under table 3) guarantee that the
sensing element is totally immerged into dimension of ther-
mowell and consequently into the piping, for best sensibility.
■
Bulb diameter
d
must be maximum 1mm less than the bore
diameter of thermowell.
■
Thermowell thread must be suitable with thermometer thread.
Then insert the instrument bulb till the bottom of thermowell,
screw the rotating connection of thermometer on thermowell
thread and orient the instrument in a position that permit an easy
reading. Then tighten with suitable key the rotating nut and verify
the solidity of the mounting.
NOTE:
In the event that the tolerance between bulb diameter and
bore diameter of thermowell is more than 1mm fill the thermowell
bore with suitable transmission fluid such as silicone oil or graphi-
te dust : this will improve the instrument performances.
3 Regulation of the instrument in
“every angle” version
Instrument case could be oriented before installation to the requi-
red inclination, up to a maximum of 90°. To do this it is necessary to
unscrew the two “A” screws, place the case in the required inclina-
tion and then screw again the two “A” screws. (see Fig. 2)
Fig. 2 – Regulation of case inclination
WARNING
Absolutely do not use the instrument case to tighten it
on thermowell. This can cause damages to the instrument.
A
